1. Field of the Invention
The present general inventive concept relates to a hybrid hard disk drive (HDD), and more particularly, to a hybrid HDD to select a data storage location without operating system (OS) support, and a data storage method thereof.
2. Description of the Related Art
The hybrid HDD is a data storage apparatus designed to minimize power consumption of the hybrid HDD, and improve performance by additionally installing a flash memory device, which is a non-volatile memory device with a relatively large volume such as 64M bytes, 128M bytes, or 256M bytes, in an existing HDD. While most read or write operations are performed in the flash memory device of the hybrid HDD, the hybrid HDD may reduce power consumption by setting a spindle motor, a voice coil motor (VCM), etc. to a power saving mode. Thus, although the power of the hybrid HDD is off, the flash memory device may store (or maintain) data as it is non-volatile.
The hybrid HDD begins to write data on a disk by waking-up a spindle motor, VCM, etc. in a power saving mode only after a memory capacity of the flash memory device reaches a certain level. A general hybrid HDD determines whether to write a predetermined data on the disk or in the flash memory device by using a non-volatile cache command (NVC) according to a Windows operating system (OS).
However, small volume HDDs such as 1.8 inch or 1.0 inch models, which are typically used in consumer electronics (CE) environments instead of a personal computer (PC) environment, should determine whether to store data on the disk or in the flash memory device to maximize performance without OS support. The CE refers to non-PC HDD applications such as a game instrument, a personal video recorder (PVR), Karaoke equipment, a MP3 player, or a media player, etc.
Generally, the flash memory device consumes less power and has faster random operation performance, but performs sequential operations at a slower rate than a HDD performs disk operations. There is no time difference when the flash memory device accesses random operations and sequential operations. But, since the disk of the HDD has a minimized seek distance in sequential operations, the disk has a shorter access time to sequential operations than the flash memory device. However, in case of a random operation of the HDD disk, a longer seek distance causes an access time to substantially increase by a unit of milliseconds.
Therefore, in order to maximize every advantage of a disk and a flash memory based on each basic feature as needed, HDD firmware requires itself to store data in an optimal storage location between a disk and a flash memory device by analyzing a pattern of write commands transferred from a host.